Seismic Response Analysis of Steel Structure Isolation System Under Long-Period Seismic Motion

Abstract

To analyze the seismic response of steel structure isolation systems under long-period seismic motion, a 9-story steel frame building was selected as the subject. Five steel structure finite element models were established using SAP2000. Response spectrum analysis was conducted on the seismic motion to determine if it adhered to the characteristics of long-period seismic motion. Modal analysis of each structural model revealed that the isolation structure significantly prolonged the structural natural vibration period and enhanced seismic performance. Base reactions and floor displacements of various structures notably increased under long-period seismic motion compared to regular seismic activity. Placing isolation bearings in the lower part of the structure proved more effective under long-period seismic motion. In seismic design engineering, it is essential to consider the impact of long-period seismic motion on structures and the potential failure of isolation bearings.